Peripheral Neuron-Organoid Interaction Induces Colonic Epithelial Differentiation via Non-Synaptic Substance P Secretion.

Background and Objectives: The colonic epithelial layer is a complex structure consisting of multiple cell types that regulate various aspects of colonic physiology, yet the mechanisms underlying epithelial cell differentiation during development remain unclear. Organoids have emerged as a promising model for investigating organogenesis, but achieving organ-like cell configurations within colonic organoids is challenging. Here, we investigated the biological significance of peripheral neurons in the formation of colonic organoids. Methods and Results: Colonic organoids were co-cultured with human embryonic stem cell (hESC)-derived peripheral neurons, resulting in the morphological maturation of columnar epithelial cells, as well as the presence of enterochromaffin cells. Substance P released from immature peripheral neurons played a critical role in the development of colonic epithelial cells. These findings highlight the vital role of inter-organ interactions in organoid development and provide insights into colonic epithelial cell differentiation mechanisms. Conclusions: Our results suggest that the peripheral nervous system may have a significant role in the development of colonic epithelial cells, which could have important implications for future studies of organogenesis and disease modeling.

Diboronic-Acid-Based Electrochemical Sensor for Enzyme-Free Selective and Sensitive Glucose Detection.

A diboronic acid anthracene-based fluorescent system for detecting blood glucose could be used for 180 days. However, there has not yet been a boronic acid immobilized electrode to selectively detect glucose in a signal-increased way. Considering malfunctions of sensors at high sugar levels, the electrochemical signal should be increased proportionally to the glucose concentration. Therefore, we synthesized a new diboronic acid derivative and fabricated the derivative-immobilized electrodes for the selective detection of glucose. We performed cyclic voltammetry and electrochemical impedance spectroscopy with an Fe(CN)63-/4- redox pair for detecting glucose in the range of 0-500 mg/dL. The analysis revealed increased electron-transfer kinetics such as increased peak current and decreased semicircle radius of Nyquist plots as the glucose concentration increased. The cyclic voltammetry and impedance spectroscopy showed that the linear detection range of glucose was 40 to 500 mg/dL with limits of detection of 31.2 mg/dL and 21.5 mg/dL, respectively. We applied the fabricated electrode to detect glucose in artificial sweat and obtained 90% of the performance of the electrodes in PBS. Cyclic voltammetry measurements of other sugars such as galactose, fructose, and mannitol also showed linear increased peak currents proportional to the concentrations of the tested sugars. However, the slopes of the sugars were lower than that of glucose, indicating selectivity for glucose. These results proved the newly synthesized diboronic acid is a promising synthetic receptor for developing a long-term usable electrochemical sensor system.

Perovskite solar cells integrated with blue cut-off filters for mitigating light-induced degradation.

The stability of methylammonium (MA)-based perovskite solar cells (PSCs) remains one of the most urgent issues that need to be addressed. Inherent weak binding forces between MAs and halides cause the perovskite structure to become unstable under exposure to various external environmental factors such as moisture, oxygen, ultraviolet radiation, and heat. In particular, the degradation of perovskite films under light exposure accelerates the deterioration of the device, mainly due to the migration of halide ions. In this study, we investigated the effect of light energy on the degradation of inverted PSCs by introducing red ( = 610-800 nm), green (500-590 nm), and blue (300-500 nm) light-pass filters. After 30 h, the inverted PSCs of blue-light-induced devices retained a power conversion efficiency (PCE) of 70%, while those of the green and red light-induced devices retained PCEs of 85% and 90%, respectively. Direct evidence of light-induced degradation was obtained by investigating morphological changes in the perovskite films and the amount of ion accumulation on the Ag electrode. This evidence highlights the varying effect of light with different energies on device degradation. Furthermore, to minimize light-induced device degradation, we designed two types of blue cut-off filters that can selectively block light ranging from = 400 to 500 nm, comprising a multilayered inorganic metasurface. An optical simulation was used to optimize the performance of the designed filters. By investigating the changes in the photovoltaic parameters and the amount of ion accumulation on the Ag electrode, we confirmed that integrating blue cut-off filters into PSCs greatly improved the operational lifetime of the devices.

Multilevel Anti-Counterfeiting Based on Covert Structural Features Embedded in Femtosecond-Laser-Treated Gold Nanocluster/Graphene Hybrid Layer.

The conventional nanoscale anti-counterfeiting scheme, exhibiting limited encoding capacity, faces growing challenges of being falsified with the advent of advanced high-resolution equipment. In this study, we propose a multilevel anti-counterfeiting device based on a femtosecond laser (fs-laser) treated plasmonic gold nanocluster/graphene (AuNC/Gr) hybrid structure integrated with a resonant cavity. The covert structural features encoded in random colored patterns, optical reflection spectra, and Raman spectra constitute three classes of anti-counterfeiting signatures, which originate from the AuNC-covered Gr, which initiates plasmonic and thermal couplings. The attendant inverted thermal distribution is presumed to confine the structural features to the AuNC-Gr interface while leaving no detectable traces on the surface of AuNC/Gr even under advanced high-resolution equipment. Therefore, the proposed approach achieves multilevel anti-counterfeiting accomplishing physically unclonable functions in the form of random colored patterns, reflection spectra, and Raman spectra. As the first report for realizing remarkable optical modulation (i.e., random colored patterns) without any surface trace or damage via fs-laser-AuNC/Gr interaction, our study also discloses the outstanding performance of Gr in fs-laser-induced optothermoplasmonic lithography on near-percolation metal films. Simultaneously, the demonstrated fs-laser-processed plasmonic hybrid structure in conjunction with a resonant cavity is anticipated to expand the encoding capabilities for nanoscale anti-counterfeiting while avoiding the risk of being imitated because of the covert structural features.

Using machine learning and liquid crystal droplets to identify and quantify endotoxins from different bacterial species.

Detection and quantification of bacterial endotoxins is important in a range of health-related contexts, including during pharmaceutical manufacturing of therapeutic proteins and vaccines. Here we combine experimental measurements based on nematic liquid crystalline droplets and machine learning methods to show that it is possible to classify bacterial sources (Escherichia coli, Pseudomonas aeruginosa, Salmonella minnesota) and quantify concentration of endotoxin derived from all three bacterial species present in aqueous solution. The approach uses flow cytometry to quantify, in a high-throughput manner, changes in the internal ordering of micrometer-sized droplets of nematic 4-cyano-4'-pentylbiphenyl triggered by the endotoxins. The changes in internal ordering alter the intensities of light side-scattered (SSC, large-angle) and forward-scattered (FSC, small-angle) by the liquid crystal droplets. A convolutional neural network (Endonet) is trained using the large data sets generated by flow cytometry and shown to predict endotoxin source and concentration directly from the FSC/SSC scatter plots. By using saliency maps, we reveal how EndoNet captures subtle differences in scatter fields to enable classification of bacterial source and quantification of endotoxin concentration over a range that spans eight orders of magnitude (0.01 pg mL-1 to 1 µg mL-1). We attribute changes in scatter fields with bacterial origin of endotoxin, as detected by EndoNet, to the distinct molecular structures of the lipid A domains of the endotoxins derived from the three bacteria. Overall, we conclude that the combination of liquid crystal droplets and EndoNet provides the basis of a promising analytical approach for endotoxins that does not require use of complex biologically-derived reagents (e.g., Limulus amoebocyte lysate).

Peroneal Tendon Subluxation and Dislocation in Calcaneus Fractures.

The present study investigated the relationship between type of calcaneal fractures and subluxation or dislocation of peroneal tendon. Also, we investigated clinical outcomes of patients with both calcaneal fractures and dislocations or subluxations of peroneal tendons in early surgical treatments (at the time of surgery for calcaneal fractures) and delayed surgical treatment (at the time of surgery for calcaneal plate removal) for dislocations or subluxations of peroneal tendons. We included 151 patients with calcaneal fractures who were followed for ≥2 years after surgery. Among them, 21 cases (13.9%) required reduction for peroneal tendon subluxation or dislocation. Reductions of peroneal tendons were performed at the time of surgery for calcaneal fractures in 11 cases, whereas the other 10 cases were performed during surgery for calcaneal implant removal. As classified by Essex-Lopresti, 94 cases (62.3%) were joint depression type and 17 (18.1%) were accompanied by dislocations or subluxations of peroneal tendons, whereas 57 (37.7%) were tongue type and 4 (7.0%) were accompanied by dislocations or subluxations of peroneal tendons. As classified by the Sanders system, 96 cases (63.6%) were Sanders A fracture lines, and 18 (18.8%) were accompanied by dislocations or subluxations of peroneal tendons. In 55 cases (36.4%) without Sanders A fracture lines, 3 (5.5%) were accompanied by dislocations or subluxations of peroneal tendons. In conclusion, calcaneal fractures with peroneal tendon dislocations are more common in joint depression type and Sander A type. Also, after a ≥2-year follow-up period, there were no significant differences in visual analog scale or foot and ankle outcome score whether reduction of peroneal tendons was done with reduction of fracture or removal of implant of calcaneus.

Light-driven diffraction grating based on a photothermal actuator incorporating femtosecond laser-induced GO/rGO.

A light-driven diffraction grating incorporating two grating patterns with different pitches atop a photothermal actuator (PTA) has been proposed. It is based on graphene oxide/reduced graphene oxide (GO/rGO) induced via femtosecond laser direct writing (FsLDW). The rGO, its controllable linewidth, and transmission support the formation of grating patterns; its noticeably small coefficient of thermal expansion (CTE), good flexibility, and thermal conductivity enable the fabrication of a PTA consisting of a polydimethylsiloxane layer with a relatively large CTE. Under different intensities of light stimuli, diffraction patterns can be efficiently tailored according to different gratings, which are selectively addressed by incident light beam hinging on the bending of the PTA. This is the first demonstration of combining gratings and PTA, wherein the GO plays the role of a bridge. The light-driven mechanism enables the contactless operation of the proposed device, which can be efficiently induced via FsLDW. The diffraction angle could be changed between 2° and 6° horizontally, and the deviation of side lobes from the main lobe could be altered vertically in a continuous range. The proposed device may provide powerful support for activating dynamic diffraction devices in photothermally contactless schemes.

Narrowband and flexible perfect absorber based on a thin-film nano-resonator incorporating a dielectric overlay.

We developed a flexible perfect absorber based on a thin-film nano-resonator, which consists of metal-dielectric-metal integrated with a dielectric overlay. The proposed perfect absorber exhibits a high quality (Q-)factor of ~ 33 with a narrow bandwidth of ~ 20 nm in the visible band. The resonance condition hinging on the adoption of a dielectric overlay was comprehensively explored by referring to the absorption spectra as a function of the wavelength and thicknesses of the overlay and metal. The results verified that utilizing a thicker metal layer improved the Q-factor and surface smoothness, while the presence of the overlay allowed for a relaxed tolerance during practical fabrication, in favor of high fidelity with the design. The origin of the perfect absorption pertaining to zero reflection was elucidated by referring to the optical admittance. We also explored a suite of perfect absorbers with varying thicknesses. An angle insensitive performance, which is integral to such a flexible optical device, was experimentally identified. Consequently, the proposed thin-film absorber featured an enhanced Q-factor in conjunction with a wide angle of acceptance. It is anticipated that our absorber can facilitate seminal applications encompassing advanced sensors and absorption filtering devices geared for smart camouflage and stealth.

All-dielectric metasurfaces for simultaneously realizing polarization rotation and wavefront shaping of visible light.

All-dielectric metasurfaces have shown unprecedented abilities to control light polarization and phase, yet most previous relevant studies have been mainly limited to cross-polarized schemes. This paper presents dielectric metasurfaces that incorporate distinct half-waveplate-like hydrogenated amorphous silicon nanoposts and are shown to manipulate the wavefront of transmitted visible light exhibiting controllable linear polarization angles. An anomalous beam deflector is designed, and high performances including an absolute deflection efficiency of 82%, a polarization conversion efficiency of 96%, and an extinction ratio of 37 dB are first demonstrated in the cross-polarized scheme. Furthermore, the anomalously deflected light could hold a high degree of linear polarization (>0.96), which can be continuously rotated by varying the incident polarization angle. Based on this principle, we fabricate a metalens and experimentally observe the light focusing phenomenon at the location designed for the cross-polarized light. Moreover, the rotation of the linear polarization angle corresponding to the output focused beam spot is successfully validated by tailoring the incident polarization angle. The developed metalens can therefore be treated as equivalent to the combination of a half-waveplate and focusing lens. The proposed ultra-thin dielectric metasurfaces, which do not require the alignment of multiple elements, could be used to facilitate the development of ultra-compact photonics systems.

Structural color filters based on an all-dielectric metasurface exploiting silicon-rich silicon nitride nanodisks.

An all-dielectric metasurface is deemed to serve a potential platform to demonstrate spectral filters. Silicon-rich silicon nitride (SRN), which contains a relatively large portion of silicon, can exhibit higher refractive indices, when compared to silicon nitride. Meanwhile, the extinction coefficient of SRN is smaller than that of hydrogenated amorphous silicon, leading to reduced absorption loss in the shorter wavelength. SRN is therefore recommended as a scattering element from the perspective of realizing all-dielectric metasurfaces. In this work, we propose and embody a suite of highly efficient structural color filters, capitalizing on a dielectric metasurface that consists of a two-dimensional array of SRN nanodisks that are embedded in a polymeric layer. The SRN nanodisks may support the electric dipole (ED) and magnetic dipole (MD) resonances via Mie scattering, thereby leading to appropriate spectral filtering characteristics. The ED and MD are identified from field profile observation with the assistance of finite-difference time-domain simulations. The manufactured color filters are observed to produce various colors in both transmission and reflection modes throughout the visible band, giving rise to a high transmission of around 90% in the off-resonance region and a reflection ranging up to 60%. A variety of colors can be realized by tuning the resonance by adjusting the structural parameters such as the period, diameter, and height of the SRN nanodisks. The spectral position of resonances might be flexibly tuned by tailoring the polymer surrounding the SRN nanodisks. It is anticipated that the proposed coloring devices will be actively used for color displays, imaging devices, and photorealistic color printing.

Effect of a Surfactant in Microcapsule Synthesis on Self-Healing Behavior of Capsule Embedded Polymeric Films.

Recently, there has been increased interest in self-healing membranes containing functional microcapsules in relation to challenges involving water treatment membranes. In this study, a self-healing membrane has been prepared by incorporating microcapsules with a polyurethane (PU) shell and a diisocyanate core in a poly(ether sulfone) (PES) membrane. Depending on the characteristics of the microcapsule, to precisely quantify the self-healing behavior and performance of the produced microcapsule embedded membranes, it is important to understand the effect of a used surfactant on microcapsule synthesis. It is noteworthy that mixed surfactants have been employed to control and tailor the size and morphology of microcapsules during the synthetic process, and the surfactant system employed was one of the most dominant parameters for affecting the healing capability of microcapsule embedded membranes. Various techniques including microscopy (optical and electron), thermal analyses (DSC and TGA), and water flux measurements have been employed. This article provides essential and important information for future research into the subtle relation between microcapsule properties with varied synthetic parameters and the self-healing behavior of membrane.

All Dielectric Transmissive Structural Multicolor Pixel Incorporating a Resonant Grating in Hydrogenated Amorphous Silicon.

All dielectric transmissive type polarization-tuned structural multicolor pixels (MCPs) are proposed and demonstrated based on a one-dimensional hydrogenated amorphous silicon (a-Si:H) grating integrated with a silicon nitride waveguide. Both bandpass and bandstop transmission filtering characteristics in the visible regime, centered at the same wavelength, have been achieved by tailoring the structural parameters including the duty ratio of the grating and the thickness of the dielectric waveguide. For the three manufactured MCPs, the transmission peak exceeds 70% for the transverse electric (TE) polarization and 90% for the transverse magnetic (TM) polarization as observed at the resonance and off-resonance wavelength, respectively. The polarization-switched transmissions are attributed to the guided mode resonance initiated by the interaction of the a-Si:H grating and the dielectric waveguide. A broad color palette covering the entire visible band was successfully realized from a suite of MCPs with varying grating pitches. The proposed structural color pixels are expected to facilitate the construction of dynamic displays, image sensors, optical data storage, security tags, and so forth.

Structural Color Filters Enabled by a Dielectric Metasurface Incorporating Hydrogenated Amorphous Silicon Nanodisks.

It is advantageous to construct a dielectric metasurface in silicon due to its compatibility with cost-effective, mature processes for complementary metal-oxide-semiconductor devices. However, high-quality crystalline-silicon films are difficult to grow on foreign substrates. In this work, we propose and realize highly efficient structural color filters based on a dielectric metasurface exploiting hydrogenated amorphous silicon (a-Si:H), known to be lossy in the visible regime. The metasurface is comprised of an array of a-Si:H nanodisks embedded in a polymer, providing a homogeneously planarized surface that is crucial for practical applications. The a-Si:H nanodisk element is deemed to individually support an electric dipole (ED) and magnetic dipole (MD) resonance via Mie scattering, thereby leading to wavelength-dependent filtering characteristics. The ED and MD can be precisely identified by observing the resonant field profiles with the assistance of finite-difference time-domain simulations. The completed color filters provide a high transmission of around 90% in the off-resonance band longer than their resonant wavelengths, exhibiting vivid subtractive colors. A wide range of colors can be facilitated by tuning the resonance by adjusting the structural parameters like the period and diameter of the a-Si:H nanodisk. The proposed devices will be actively utilized to implement color displays, imaging devices, and photorealistic color printing.

Polarization-Controlled Broad Color Palette Based on an Ultrathin One-Dimensional Resonant Grating Structure.

Highly efficient polarization-tuned structural color filters, which are based on a one- dimensional resonant aluminum grating that is integrated with a silicon nitride waveguide, are proposed and demonstrated to feature a broad color palette. For such a metallic grating structure, transmissive color filtering is only feasible for the incident transverse-magnetic (TM) polarization due to its high reflection regarding the transverse-electric (TE) case; however, polarization-tuned customized colors can be efficiently achieved by optimizing the structural parameters like the duty ratio of the metallic grating. For the fabricated color filters, the transmission peaks, which are imputed to the resonance between the incident light and the guided modes that are supported by the dielectric waveguide, provided efficiencies as high as 90% and 70% for the TM and TE polarizations, respectively, as intended. Through the tailoring of the polarization, a group of filters with different grating periods were successfully exploited to produce a broad color palette spanning the entire visible band. Lastly, a nanoscale alphabetic pattern featuring a flexible combination of colorations was practically constructed via an arrangement of horizontal and vertical gratings.

Angle-tolerant linear variable color filter based on a tapered etalon.

We propose and fabricate a linear variable color filter (LVCF) that possesses an enhanced angular tolerance in conjunction with a wide linear filtering range (LFR) by taking advantage of an Ag-TiO2-Ag configuration. The TiO2 cavity is tapered in thickness along the device so that the resonance wavelength can be continuously tuned according to the position. In addition, the metal-dielectric-metal structure is overlaid with a pre-designed graded anti-reflection coating in SiO2 to complete the etalon, thereby maximizing the transmission efficiency across the entire device. The tapered dielectric layers in the proposed filter were fabricated via glancing angle deposition without the help of any mask or moving parts. The center wavelength was scanned from 410 nm to 566 nm, resulting in an LFR of 156 nm, and the overall spectra exhibited an approximate peak transmission of 40% and spectral bandwidth of 68 nm. The angular tolerance was as large as 45°, incurring a fractional wavelength shift below 4.2%. The resonance wavelength was verified to be linearly dependent on the position, providing a linearity beyond 99%. The proposed LVCF will thus be actively utilized in a portable micro-spectrometer and spectral scanning device.

D-Allulose Production from D-Fructose by Permeabilized Recombinant Cells of Corynebacterium glutamicum Cells Expressing D-Allulose 3-Epimerase Flavonifractor plautii.

A d-allulose 3-epimerase from Flavonifractor plautii was cloned and expressed in Escherichia coli and Corynebacterium glutamicum. The maximum activity of the enzyme purified from recombinant E. coli cells was observed at pH 7.0, 65°C, and 1 mM Co2+ with a half-life of 40 min at 65°C, Km of 162 mM, and kcat of 25280 1/s. For increased d-allulose production, recombinant C. glutamicum cells were permeabilized via combined treatments with 20 mg/L penicillin and 10% (v/v) toluene. Under optimized conditions, 10 g/L permeabilized cells produced 235 g/L d-allulose from 750 g/L d-fructose after 40 min, with a conversion rate of 31% (w/w) and volumetric productivity of 353 g/L/h, which were 1.4- and 2.1-fold higher than those obtained for nonpermeabilized cells, respectively.

Trans-Reflective Color Filters Based on a Phase Compensated Etalon Enabling Adjustable Color Saturation.

Trans-reflective color filters, which take advantage of a phase compensated etalon (silver-titania-silver-titania) based nano-resonator, have been demonstrated to feature a variable spectral bandwidth at a constant resonant wavelength. Such adjustment of the bandwidth is presumed to translate into flexible control of the color saturation for the transmissive and reflective output colors produced by the filters. The thickness of the metallic mirror is primarily altered to tailor the bandwidth, which however entails a phase shift associated with the etalon. As a result, the resonant wavelength is inevitably displaced. In order to mitigate this issue, we attempted to compensate for the induced phase shift by introducing a dielectric functional layer on top of the etalon. The phase compensation mediated by the functional layer was meticulously investigated in terms of the thickness of the metallic mirror, from the perspective of the resonance condition. The proposed color filters were capable of providing additive colors of blue, green, and red for the transmission mode while exhibiting subtractive colors of yellow, magenta, and cyan for the reflection mode. The corresponding color saturation was estimated to be efficiently adjusted both in transmission and reflection.

Production of d-psicose from d-fructose by whole recombinant cells with high-level expression of d-psicose 3-epimerase from Agrobacterium tumefaciens.

The specific activity of recombinant Escherichia coli cells expressing the double-site variant (I33L-S213C) d-psicose 3-epimerase (DPEase) from Agrobacterium tumefaciens was highest at 24 h of cultivation time in Terrific Broth (TB) medium among the media tested. The contents of crude protein and DPEase in recombinant cells at 24 h were 37.0 and 8.6% (w/w), respectively, indicating that the enzyme was highly expressed. The reaction conditions for the production of d-psicose from d-fructose by whole recombinant cells with the highest specific activity were optimal at 60°C, pH 8.5, 4 g/l cells, and 700 g/l d-fructose. Under these conditions, whole recombinant cells produced 230 g/l d-psicose after 40 min, with a conversion yield of 33% (w/w), a volumetric productivity of 345 g/l/h, and a specific productivity of 86.2 g/g/h. These are the highest conversion yield and volumetric and specific productivities of d-psicose from d-fructose by cells reported thus far.

Unveiling of novel regio-selective fatty acid double bond hydratases from Lactobacillus acidophilus involved in the selective oxyfunctionalization of mono- and di-hydroxy fatty acids.

The aim of this study is the first time demonstration of cis-12 regio-selective linoleate double-bond hydratase. Hydroxylation of fatty acids, abundant feedstock in nature, is an emerging alternative route for many petroleum replaceable products thorough hydroxy fatty acids, carboxylic acids, and lactones. However, chemical route for selective hydroxylation is still quite challenging owing to low selectivity and many environmental concerns. Hydroxylation of fatty acids by hydroxy fatty acid forming enzymes is an important route for selective biocatalytic oxyfunctionalization of fatty acids. Therefore, novel fatty acid hydroxylation enzymes should be discovered. The two hydratase genes of Lactobacillus acidophilus were identified by genomic analysis, and the expressed two recombinant hydratases were identified as cis-9 and cis-12 double-bond selective linoleate hydratases by in vitro functional validation, including the identification of products and the determination of regio-selectivity, substrate specificity, and kinetic parameters. The two different linoleate hydratases were the involved enzymes in the 10,13-dihydroxyoctadecanoic acid biosynthesis. Linoleate 13-hydratase (LHT-13) selectively converted 10 mM linoleic acid to 13S-hydroxy-9(Z)-octadecenoic acid with high titer (8.1 mM) and yield (81%). Our study will expand knowledge for microbial fatty acid-hydroxylation enzymes and facilitate the designed production of the regio-selective hydroxy fatty acids for useful chemicals from polyunsaturated fatty acid feedstocks.

Omnidirectional color filters capitalizing on a nano-resonator of Ag-TiO2-Ag integrated with a phase compensating dielectric overlay.

We present a highly efficient omnidirectional color filter that takes advantage of an Ag-TiO2-Ag nano-resonator integrated with a phase-compensating TiO2 overlay. The dielectric overlay substantially improves the angular sensitivity by appropriately compensating for the phase pertaining to the structure and suppresses unwanted optical reflection so as to elevate the transmission efficiency. The filter is thoroughly designed, and it is analyzed in terms of its reflection, optical admittance, and phase shift, thereby highlighting the origin of the omnidirectional resonance leading to angle-invariant characteristics. The polarization dependence of the filter is explored, specifically with respect to the incident angle, by performing experiments as well as by providing the relevant theoretical explanation. We could succeed in demonstrating the omnidirectional resonance for the incident angles ranging to up to 70°, over which the center wavelength is shifted by below 3.5% and the peak transmission efficiency is slightly degraded from 69%. The proposed filters incorporate a simple multi-layered structure and are expected to be utilized as tri-color pixels for applications that include image sensors and display devices. These devices are expected to allow good scalability, not requiring complex lithographic processes.